Components, Projection, and Resolution

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brinlin
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Printed problem text: Suppose u = <3, -4> and v = <-3, 1>. (a) Calculate the component of u along v. (b) Calculate the projection u1 of u onto v. (c) Resolve u into two vectors, where one is parallel to v and another is orthogonal to v.
 
Where are you getting these problems? You seem to be saying you know nothing at all about trigonometry!

Imagine the vectors u and v with their "tails" together. Draw a perpendicular from the tip of u to v. The "component of u along v" is the distance from the common tails to that perpendicular. So you have a right triangle where the length of the hypotenuse is the length of u and one angle is the angle between u and v. The "component of u along v" is the length of the "near side" of that triangle so you will need the cosine of the two vectors. If you know that the dot product of two vectors is $u\cdot v= |u||v| cos(\theta)$ then that will be easy to calculate.